The present invention is applicable to rack body trucks, and other vehicles which have features like such trucks. In a typical rack body truck, the flat bed of the truck, for carrying things, is enclosed by railings, or racks. Typically, each rack is held in place by downward protruding members, or stakes, which insert into pockets spaced apart along the edge of the bed. If desired, the racks may be lifted up and removed, to create a totally accessible flat bed. Typically, racks at least run along opposing sides of the bed, in the front-back direction. Sometimes, there is a rack running sideways across the rear or tail end of the bed, so the total rack assembly runs in the shape of a U. The forward portion of the bed may be only bounded by the rear portion of the cab; or, there may be another fence or rack which is often not readily removable, so the rack will define a rectangular enclosure. A rack running along the edge of a bed may often be segmented into separate units, for convenience in handling.
Typically, the bed of a flat bed truck is substantially raised above the ground, since it extends outwardly over the rear wheels of the vehicle. And, often things have to be put on the bed from the ground surface on which the vehicle rests. In such situations, one common way of moving heavy objects to or from the bed, particularly objects which have wheels, is to roll them up or down sloped ramps. Typically, the ramps run parallel to the vehicle length, out and downwardly, from the rear edge of the bed. Ramps are usually used as pairs, are made of metal, such as steel or aluminum, and have continuous or perforated working surfaces. Ramps must be sufficiently long, to make the angle from the horizontal slight enough, so excess force is not necessary for pushing or for restraining an object moving along the ramp, and to make it feasible for a self-powered vehicle to move up the ramp. For flexibility, it is desirable to be able to change the spacing between the pieces of a ramp pair, to accommodate different width vehicles or objects being carried. Obviously, ramps can be and are used for sliding as well as rolling of objects onto or off of a bed.
It is common that ramps have to be stowed and carried on the vehicle, so they are available at the remote locations, for loading or discharge. Of course, if the body design permits, a special stowing location can be configured under the bed. It is more usual to simply stow the ramps on the bed with the cargo, by laying them alongside one or both racks or on top of the cargo. Of course, when doing that, they take up cargo space. Alternately, ramps may be hung from the exterior of one or both racks. But, that expands the width of truckand puts the ramps in a location where they are more vulnerable to damage.